Microscopic flakes of graphene can add strength and durability to concrete - but also raise cost and safety concerns.

New forms of concrete can trap and store the greenhouse gas carbon dioxide, break down pollutants from exhaust fumes, and help protect aging infrastructure by sealing cracks as they form. And now scientists in the U.K. have developed a “green” concrete that they say is more environmentally friendly than the ordinary stuff, as well as more durable and more than twice as strong.